U.S. Pat. No. 4,821,114 has disclosed an optical illumination system having a filter wheel and a white light source in the form of a lamp. In this case, blocking filters, such as absorption filters and dichroitic filters, for example, are used. They are inserted into the beam path of virtually point light sources such as xenon high-pressure discharge lamps. A continuous change in color is therefore only possible with a plurality of filter wheels and needs to be realized in a complex manner by mechanical means. The filter wheels are positioned one behind the other and rotated appropriately. The control is complex and the filters are very expensive.
Control for groups of LEDs is specified, for example, in U.S. Pat. Nos. 5,515,136 and 6,630,801. DE-Az 10 2005 041 319.6 has described a module in which a plurality of high-efficiency LEDs are combined on one printed circuit board. These are then imaged onto one point.